Study On Deformation Mechanism And Control Technology Of The Underground Engineering Cavern Wedges

With the development of human society and the progress of science and technology,the exploitation of underground space is a kind of phenomenon to produce, which hasplayed an important role in the whole world.Gradually, the exploitation of surface couldnot content daily lives and traffic, etc. With the development of underground space,efficient space used by people increased several times. Consequently, it led to theoccurrence of various geotechnical hazards occurred in underground space development,and Wedge failure was one of them.In order to research the stability and failure mode of the underground cavern, tostudy the formation mechanism of wedge and to interpretate the fragmentation degree ofrock by using the limit equilibrium method, the block theory, stereographic projectionand other research methods. The wedge composed different fragmentation degree ofbroken rock and it had proposed the corresponding control mechanism.1To judge underground engineering wedge simply from geometry is not correct. Itneeded some other methods, then, to analyze on the formation mechanism of the wedgefactor from the geological and Human factors, which means the wedge failure can bedivided into two types as single failure of sliding failure and double sliding. A wedge inthe structural plane (joints, faults and so on) is formed under the action of cutting,however, the space position and its size are uncertain.2Discrimination of underground cavern sliding wedge with stereographicprojection method and the block theory, by virtue of the accurate geological data andother basic data, using the stereographic projection judged sliding wedge, the vectormethod is capable of key blocks and their motion form of judgment the few groupstructure. For several different groups of combination relations, it determines thepossible unstable wedge structure of the space combination form.3Without considering the groundwater and only with the effect of blastingvibration load, to take mechanics analysis of the wedge stability by limit equilibriummethod.The wedge by force to the position on the gravity center is analyzed, puttingforward the judgment condition of sliding along the sliding surface. Assume that α is theangle between normal direction and horizontal direction, ξis the angle between verticalline on each edges by the center of gravity O and the horizontal direction, θ is the anglebetween vertical line on each surfaces by the center of gravity O and the horizontaldirection. According to the relationship between α and ξ or θ, moreover, with the forcedirection from F, the stability coefficient of wedge is gained.4To analysis on the failure of underground cavern wedge, to divide thefragmentation degree of rock, and according to the different degree of rock massfracture formed wedge, it puts forward pertinence control measures.